1. Field of the invention
The present invention relates to an optical interconnection device and a photoelectric mixedly mounted device (or optical electric hybrid device) including an optical waveguide and an optical interconnection port for optically connecting a signal between electric chips on an electric circuit board and mutually between electric circuit boards and so on and an electronic equipment using them.
2. Related Background Art
A large number of highly integrated LSI chips are used to enhance performance of mobile equipments, digital AV (audiovisual) equipments and so on represented by personal computers, cellular phones and PDAs that support the advanced information society, and a mounting technology for operating them at high density and high speed is searched for. In this regard, the mounting technology in the past using only electric connections has shown its limit as to solutions to the problems of transmission delay and crosstalk, reduction in electromagnetic interference (EMI) and so on, and so a method of using optical interconnection together with it is now considered.
There are some proposals of examples of applying the optical interconnection between the chips. For instance, it is considered that the method of using a slab waveguide comprised of an organic polymer formed on a flat substrate as a transmission medium has advantages of matching well with the LSI chips and a board and packages for mounting them, being easy to manufacture and capable of free connections between the chips compared to the method of creating a linear optical waveguide (Japanese Patent Application Laid-Open No. H8-293836 for instance).
The example disclosed in the patent laid-open gazette is shown in FIG. 8. An insulating layer 208 of a substrate 201a having an optical waveguide, layer encapsulated by a polymer sealant 209 is equipped with transmission elements 204 and 206 and a reception element 205, and has an LSI board 202 implemented to realize signal transmission between LSIs by using a slab optical waveguide 201b (signal light 203). A hologram 207 is used for optical coupling between the transmission elements 204, 206, reception element 205 and waveguide 201b, and a coupling state between the elements is further controlled by an element for controlling a wavelength.
However, as the method disclosed in the patent laid-open gazette controls a connection between the LSI chips by using a wavelength control element, high stability is required of the transmission elements and wavelength control element so that it may be difficult to be implemented in the proximity of the LSI where temperature environment is not necessarily good.